Mixing Pextral's Two Bath; Substitute for Sodium Hydroxide?

[gainer]

srs-muchisma gracias

the unblinkingeye link was what i needed

ole-it was not my intention to dump bleach in the developer-just that if you need sodium hydroxide and it is allready waiting for you on the shelf in the supermkt, re cheapo house brand "ultra bleach" -active ingrdnt sodium hydroxide @ approx 1% and if it is needed for the mix why not try that instead of diluiting down draino? but thanks for the heads up-i'm chemically challenged and dislexic so i need to be reeled in at times

vaya con dios

I keep hypochlorite far from film unless I want to remove the emulsion for some reason, such as to measure base density. If you want to see the extreme, dunk a piece of junk film in chlorine bleach. Very dilute hypochlorite may be no worse than some chlorinated water from some public water supplies, but I don't like that either.

[Tom Hoskinson]

Thanks for the suggestion Tom. I have some ascorbic acid handy, and will try it. However, would that not reduce the shelf life of the catechol solution?

Justin

Possibly, but that won't matter much if you are using this developer as a ONE-SHOT.

[gainer]

Thanks for the suggestion Tom. I have some ascorbic acid handy, and will try it. However, would that not reduce the shelf life of the catechol solution?

Justin

If you want to add ascorbic acid without changing the acidity of the solution, mix it with baking soda in a little water and wait for the effervescence to subside before adding it to the solution. 1 level teaspoon ascorbic acid plus 1/2 level teaspoon of baking soda (sodium bicarbonate) in a couple of ounces of water gives the equivalent of 4 grams of ascorbic acid at near neutral pH.

[gainer]

I forgot to mention that the added ascorbate will not reduce the shelf life of the catechol.

[Murray Kelly]

Would the sodium carbonate bath be reusable, or is it one-shot?

In a 2-bath the carbonate is reusable.
Murray

[Justin Low]

Thanks for the advice. I've tried a roll with solution A consisting of 1% catechol, 0.5% ascorbic acid, B of 5% sodium carbonate.

See from this picture on: http://www.flickr.com/photos/justinlow/630686605/

I don't see a difference in the degree of graininess, or any substantial change. I will probably give it one last go with sodium sulfite in place of the ascorbate, but I'm not too optimistic about grain reduction.

Looks like I shall be sticking with Pyrocat-M for now.

[Ole]

In a 2-bath the carbonate is reusable.
Murray

In Pextrals, the alkali bath is resuable. But as soon as you turn the light on you will wish to discard it even after one single use; for reuse keep the light off.

It looks dreadful and gungy...

[z-man]

If you want to add ascorbic acid without changing the acidity of the solution, mix it with baking soda in a little water and wait for the effervescence to subside before adding it to the solution. 1 level teaspoon ascorbic acid plus 1/2 level teaspoon of baking soda (sodium bicarbonate) in a couple of ounces of water gives the equivalent of 4 grams of ascorbic acid at near neutral pH.

sodium/and/or magnesium ascorbate powder avilable here in nyc health/whole food stores in 8oz and up

it seems people object to the acidity of ascorbic acid-i was looking for straight ascorbic acid and no one carries it here unless you buy it in caps-easy to measure out 1 gr am a time but very costly

now foods website says that sodium ascorbate is made by combining ascorbic acid and baking soda

hey gadget-can you direct me to your articles re anti freeze for mixing non oxidising vit c formula??

i can't spend more than 15mins at a time in front of crt due to damage to 5 cervical vertebre without having to double my morphine load and then i nod out and wake up 2 hrs later so a link or 3 would be much appreciated

vaya con dios

[gainer]

First, sodium ascorbate is very soluble in water but not in glycol or TEA. Ascorbic acid is available from NOW Foods and from www.chemistrystore.com. Magnesium ascorbate is, I think, not very soluble in either water or glycol.

I don't remember the issue, but the original article describing the use of antifreeze was in Photo Techniques magazine, which has an internet site. I think you can search it. Automobile antifreeze is nearly all glycol. The ordinary one is ethylene and the "safe" one is propylene glycol. The propylene glycol as well as TEA also are available at www.chemistrystore.com at about $16 per gallon + shipping.

Can you not get or have someone make an overhead mount for your display so that you can view it from a reclining position with more support for your head to take the strain off your spine?

Any of my recipes in APUG that call for glycol can use automobile antifreeze. When I was able to get the straight glycol, I substituted ounce for ounce for the antifreeze. You get some color with the antifreeze, free of charge.

[gainer]

I forgot to say that the web site for Photo Techniques is www.phototechmag.com.